1. Field of the Invention
The present disclosure relates to wireless communication systems, and more particularly to production testing of wireless communication systems.
2. Related Art
When communication circuits, such as wireless transmitters, are initially powered up, packets that are initially transmitted can have varying power levels and/or carrier frequencies. Therefore, when testing communication circuits it is desirable for the communication circuit to stabilize in order to get an accurate and stable measurement. For example, if a testing system measures a first packet transmitted by the communication circuit after powering up, the measurement may not be representative of the communication circuit during typical use.
As such, prior art testing systems introduce a time delay after powering up the communication circuit. After the time delay, the communication circuit has stabilized and the testing system can begin taking measurements of packets transmitted by the communication circuit. The time delay must be long enough to ensure that the communication circuit has reached stable operation. However, the time delay may not be constant for every communication circuit due to factors such as heat, control algorithm variations, absolute phase variations, settling time variations, and other known factors. In addition, the testing system may perform other tasks in parallel, which can cause the time delay to vary.
In some communication circuits, such as WiMAX circuits for example, testing typically starts after the circuit has synchronized with the testing system. In these communication circuits, the testing system polls the communication circuit to determine whether it has synchronized. After synchronization, the testing system can introduce a time delay before measuring test packets transmitted from the communication circuit.
Because the time delay required for the communication circuit can vary, many prior art testing systems are designed for a worst case time delay for the communication circuit to stabilize. As such, prior art testing systems waste time waiting for the worst case time delay to expire even if the communication circuit has already stabilized. Therefore, is it desirable, among other things, provide an apparatus and method to test communication circuit in a more time-efficient manner.